Gas furnaces are also often known as domestic furnace or home furnace. These domestic furnaces are used by people in their homes to keep the air warm. Unlike other furnaces that are used to melt metals or other substances, the domestic furnace produces a relatively smaller amount of heat that is used to only make the surroundings warm.
The gas furnace is a permanently installed heating facility. In the initial stages of the development of domestic heating furnaces, the fuel utilized was wood, oil or coal. Later on, to cut the costs of operation and also due to environmental issues, furnaces that used natural gas started being widely used by households. In nations like the United States of America, the gas furnace is universally accepted by home owners. Most of the gas furnaces use LPG that is liquefied petroleum gas for operation. Some variants of this furnace have also evolved, that use methane gas or bio-gas
Working of a Gas Furnace
Before we understand how does a gas furnace work, one needs to know the parts of a gas furnace. A domestic gas furnace is principally divided into three sections. The first section is the made up of the burners, heat exchangers, draft inducer and venting. The second section is made up of controls and safety devices and the third section is made up of the blower and air movement. All the gas furnace parts work in cohesion to make the gas furnace work.
The furnace combines air and fuel (in this case gas) and the mixture is ignited. The resultant flame is then used to heat the air. This air is then circulated throughout the house. This heating process starts in the burner of the furnace, which is controlled by a thermostat. Sometimes there are two burners, in cases where a huge volume of air is to be heated. When the temperature of the house drops down, the thermostat alerts the furnace. The mixture of gas and air slowly starts entering the burner of the furnace and is ignited as a result of an electronic igniter. The air in the burner thus gets drastically heated and starts rising through the heat exchanger which is situated above the burner. It then spreads inside the housewarming it up, while the exhaust exits the furnace from a vent and is let outside the house.
In the meantime, fresh air is pulled into the furnace with the help of an electric fan. The air comes in through a large flat grill in the furnace and passes into an enclosure known as the plenum. The plenum is located opposite the heat exchanger. The heat exchanger heats the air coming in the plenum, which gets heated very quickly as a result of the high pressure. The heated air is then passed out of the furnace, into the house. This process is repeated till the temperature of the house reaches a specific level after which the thermostat stops the heating process.
Nowadays, many people have started using electric furnaces to keep their homes warm. Innovators have also come up with concepts like geothermal heaters that are more environment friendly. Geothermal energy heaters utilize the heat inside the earth for heating purposes. Many other innovative domestic furnaces and heaters, like, solar heaters are also in the process of development.